Local citizens of Dortmund, Germany, are growing their own food by renting plant beds at the newly opened aquaponics site at the former Hansa coking plant. This ‘rent-a-bed’ system was one of the offers presented at the opening ceremony of the greenhouses earlier this month. Around 55 visitors attended the ceremony, where they had the opportunity to participate in a guided tour of the greenhouses and learn more about the project and aquaponics concept.

Aquaponics is a sustainable, water-saving and soil-less system for food production, which is particularly suited to growing food in post-industrial areas where the soil may be contaminated. It is the combination of raising fish in tanks, whose wastewater provides the nutrients needed to feed the growing plants. In Dortmund the local proGIreg team not only developed the technical concept further, but also the economic model of the site. The focus is not to sell products from these greenhouses, but instead, to rent out the aquaponic beds to locals, in a similar way to the rent-a-field business model, that is often successful in Urban Agriculture.  By separating the economics side of the concept from production quantity and quality, the researchers hope to achieve a financially stable and sustainable operational model. The replicable system can be run by an association, a cooperative or a conventional company.

"Potential users are people who would like to produce their own sustainably healthy food themselves, but for whom, for example, a classic allotment garden means too much maintenance effort," explains Prof. Dr. Wolf Lorleberg, University of Applied Sciences of South Westphalia. The plants of the aquaponics system are always optimally watered and fertilized, and there are no weeds to weed. "Chemical pesticides are not used because of the fish," says Lorleberg. In addition to the individually-rented beds, there are also community beds, from which the users take as much as they need for cooking in small quantities. In addition, the plan is to also grow community potatoes, tomatoes, peppers and chillies, so that the users have a good range of products available.

Dortmund has accompanied the project throughout: "As the owner of the Hansa coking plant, we support the project because it promotes ecologically sensible use of resources and a participatory approach," says Ursula Mehrfeld, Managing Director of the Foundation for Industrial Monument Preservation and Historical Culture (Stiftung Industriedenkmalpflege und Geschichtskultur). The site will be operated jointly by the Urbanisten and the University of Applied Sciences of South Westphalia until the end of the project. Coming up in 2027, the site will be a key exhibit at the International Garden Exhibition taking place in the Ruhr area.